Cord stretching apparatus



July 5, w49 R; cz. YOUNG ET AL I 474,927

CORD STRETCHING APPARATUS Filed June `24, 1947 z sheets-Sheet 1' R. C. YOUNG ET AL CORD STRETCHING APPARATUS July 5,` 1949.

5 Sheets-Sheet 2 Filed June 24, 1947 INVENTORS C .YOU NG 4 lFiled June 24, 1947 s sheets-sheets July 5 1949- A --R. c.YouNG ETAL 1 1 2,474,927

CORD STRETGHING 'APPARATUS Patented July 5, 1949 CORD STRETCHING APPARATUS Ray C. Young and John J. Brown, New Orleans, La., assignors to the United States of America as represented by the Secretary of Agriculture Application June 24. 1947, serial No. '156.608 s claims. l(ci. ca -71.3)

(Granted under the act of March 3, 1883, al

amended April 30, 1928; 370 0. G. 757) This application is made under the act ot March 3, 1883, as amended by the act of April 30. 1928, and the invention herein described and claimed. if patented, may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment to us of any royalty thereon.

Our invention relates to the stretching of filaments, such as cotton cord used in pneumatic tires, belts, and mechanical sewing threads.

The stretch in cotton tire cord under constant tension is not uniform because of the nature of its construction. When laid parallel to each.

other in tire plies and belting, the cords must be balanced throughout their length and in relation to each other. To achieve this result we-provide means for maintaining uniform tension on the cord, which tension remains constant despite variations in the percentage stretch caused by lack of uniformity in the cord.

To accomplish these objects we employ a mechanism which applies a constant force to tension the cord. This mechanism is designed to move in unison with or in proportion to the percentage elongation or stretch in the cord. The movement of said mechanism is transferred to a device which takes up slack in the cord caused by excessive stretch.

In one aspect, the invention comprehends a textile strand stretching apparatus comprising a forward roll and a rearward roll about each of which the strand is wrapped, speed-varying means to cause the peripheral speed of the rearward roll to lag behind that of the forward roll, means for applying a constant force to that portion of the strand extending between the rolls to apply tension thereto, an element that moves in response to variations in the amount of stretch of that portion, and actuating means responsive to the movement of the element to cause the speed-varying means to increase the said lag when the stretch increases and to decrease said lag when the stretch decreases.

The above-mentioned purposes are attained by means of the specific embodiment shown in the drawings, in which:

Figure 1 is a three-dimensional pictorial view of the machine;

Figure 2 is a sectional view of the variablespeed grip roll for the cord, oi' the constant-speed grip roll for the said cord, and of the actuating means for varying the speed;

Figure 3 is an exploded view of the variablespeed actuation means;

Figure 4 is an end view of the actuating arm, illustrating the disposition of the crank pins:

Figure 5 is a view of the hand-operated lever assembly and automatic-knock-oif device;

Figure 6 is a diagrammatic view illustrating the path of the cord as it travels through the machine;

Figure 7 is an enlarged view of a part of the lever assembly and Figure 8 is a view of a cord roll showingv the v-shaped cord gripping slot in the groove.

I'he path of the cord or strand is as follows:

The cord I is run from supply package or spool 2 over idling sheave 3, and then through tensioning device 4, which latter brings 'the cord to slight tension at this point and provides even tension in the cord entering the stretching mechanism. From" 4 the cord passes under idling sheave 5, over idling sheave 6, once around variable-speed grip roll 'I, and then over idling sheave 8. The cord is under tension at this point. It then passes under and around dancer sheave 9 (Figs. 1 and 6) and over idling sheave 8. From sheave 8' the cord passes once around constantspeed grip roll I0 which is preferably of the same diameter as variable-speed grip roll 1. The cord is then guided by idling sheaves I I and I2 to automatic knock-oil device I3 from which it passes to wind-up package 53. Sheaves 8 and 8' rotate independently. Tensioning device 4 comprises two spring-pressed discs between which the cord passes.

Constant tension is maintained on the cord by dancer sheave 9 which is freely suspended by the cord strands (Fig. 6). Sheave 9 is mounted by bracket I2I upon the upper end of standard I3I. The latter is free to move up and down, being slidably supported in vertical position by frame bracket I4, its lower end being supported in fixed pipe I5. Means is provided for applying a predetermined and downwardly directed force to standard I 3 I, and thereby to sheave 9. This comprisesweights I6 supported upon a shelf I1 attached to the standard. The height of shelf I'I above guide pipe I5 is conveniently such that when the supply package 2 runs out, the dancer shelf I'I will drop down upon and rest upon pipe I5. l

Standard I3I carries a pin I8 that fits in a slotted arm of lever I 9. Pin I8 may be fastened in place on Ill by means of a set screw (not shown). Downward movement of standard I3I, and dancer sheave 9, causes upward movement of the left end (in Fig. 1) of the lever arm I9 and upward movement of rods 20 and 2| and rocker arm 22. Lever I9 pivots upon cap screw 30 fastened to the frame. Rocker 22 is fastened t0 crank rod 23 so that upward movement of the rocker arm rotates rod 23 clockwise, in Figure 1. Formed on the ends of the rod 23 are two parallel crank pins 24 and 25 (Fig. 2) eccentrically disposed at 180, as shown in Figure 4. Crank pins 24 and 25 f'lt into holes in blocks 26 and 21. The blocks are free to reciprocate in slots 23 and 23 (Fig. 3) formed in thrust bearings 30 and 3|. Pins 24 and 25 are mounted in oil impregnated bronze bushings 34 and 35 carried in the holes in blocks 26 and 21. The thrust bearings are slidably mounted on the shafts by conventional slot and key. Rotation of rod 23 causes blocks 23 and 21 to transmit their axial motion to the thrust bearings, the latter being moved in opposite directions along shafts 32 and 33. This controls the speed ratio between grip rolls 1 and it. Springs may be provided to retract thrust bearings 30 and 3| They arek not necessary since the moving V-belt 60 running from |050' to 1'53 will cause the retraction.

Main drive shaft 36 is connected to the source of power. Sheave 31 mounted on 36 moves V- belt 38 and also sheaves 39 and 40 which are rotatably mounted upon a rocker arm 4|. The operation of the arm will be described below. When the arm is lowered, V-belt 43 is engaged and operated by sheave 40. Belt 4-3 drives belt sheave 50 and cord roll I0 (Fig. 2) at vconstant speed. Sheave 50 drives belt 5| whichoperates the driving roll 52 of the wind-up package roll 53, by means of sheaves 54 and 55, belt 56 and sheave 51. Roll 53 is frictionally driven by 52. Sheave 54 is a variable pitch sheave used to adjust the speed of wind-up package 53. for correlation with the speed of cord roll i0. Sheave 54 is adjustable by hand to suit different gauges of cord. i 'f Knock-off spool or strand feeler I3 is mounted upon the end o'f a spring 84 (Fig. 5). The other end of the spring is attached to an arm 35 which is pivotally mounted on the rod 65. In Figure 5, spring -64 is shown in released position, the spring extending downwardly. Part of the spring is shown broken away, so as not to obscure the other parts. Also attached to the arm 65 is a catch 61. When the cord breaks, spool i3 and spring 64 are released permitting catch 61 to fall into position to be engaged by the lug 68. The lu is oscillated continually by shaft 69. Lug 38 pulls the catch down and with it rod 65. One end of rod 66 is attached to hand-operated link 45 and to the knee joint bearing 10. The lowering of the rod `6E lowers joint bearing 10. retracts links.

46.-46, and raises arm 4| to idling position, in which position V-belt 43 is slack. The operation of the knock-off device proper is similar to that of devices known to persons skilled in this art. A similar spring, strand feeler, and oscillating lug are described in U. S. Patent 2,226,135 to Newton et al., on page 2. This permits themain drive shaft to continue running and to drive the remaining stretching machines when more than one unit is attached to the Winder.

Arm 4| and attached lever 43 pivot on shaft 36. When handle 42 is moved in the direction shown by the arrow in Figure 5, links 44 and 45 raise knee joint bearing 10. Since the bar 1| is attached at one end to the knee joint bearing' and at its other end to the rod 12 (Fig. 1), raising the knee joint bearing 10 causes links 46-46' to move lever 48 in the direction shown by arrow in Figure 5. This eifectuates downy 4 ward movement of rocker arm 4| and of the shaft 13, upon which sheaves 39 and 40 are rotatably mounted, and causes tightening and operation of the belt 49. Linkage 43-43 is adjustable in length lby turning screw buckle 41.

The displacement of thrust bearing 30 toward cord roll I0 (Fig. 2) moves belt sheave 50 toward the roll. This movement increases the effective diameter of the pulley formed by conical surface i0' of roll I3 and conical surface 50' of sheave 50. The displacement of sheave 5|) toward |0 coincides in time and extent with the displacement of c'onical plate 53 away from cord roll surface 1. V-belt 60 (Fig. 1) is mounted on surfaces i3' and 53 and in the groove formed between plate 59 and surface 1'.

Pins 58 (Fig. 2) transmit the rotary motion' of sheave 50 to roll i0. The pins are fastened in sheave 50 and slide in holes in sheave or roll I0. Like pins are provided for plate 58.

As shown in Figures 2 and 8, cord rolls 1 and i0 are each provided with a V-shaped large peripheral groove. Side 8| of the groove is at '15 to a plane perpendicular to the axis of the roll, side 82 is at 45 to the vertical. The longer side 8| of the groove of roll i0 is opposite the shorter side 82 of the groove of roll 1. In the lowermost part of said grooves, winch grooves are preferably 1/8 deep, are formed peripheral cord slots 6| and A32. These slots are likewise V-shaped in cross section and are 11s deep, the sides forming an angle of 15. The bottom of each slot is .008 inch in radius. These dimensions were employed for tire cord having a diameter of .025 to .040. These slots contribute greatly to the utility of the device since they reduce the tendency of the cord to slip.

When pin I8 lowers, due to excessive stretch in the cord strands that support weighted dancer sheave 3, cord grip roll 1 is caused to slow down. To accomplish this, crank rod 23 is fastened by set screw (not shown) to rocker arm 22 in such position that rotation of the rod clockwise in Figure 1 will move bearing 3| to the right in Figure 1 to increase the effective diameter of the sheave formed by conical plate 53 and conical face 1 of roll 1 and simultaneously move bearing 30 to the left in Figure 1 to decrease the effective diameter of the sheave formed by conical surfaces 50' and I0'. The slowing down of roll 1, with respect to roll i0, adjusts the tension on the cord. When the stretch, or percentage increase in length, of the cord decreases. pin I8 will rise, causing the roll 1 to speed-up. and approach the speed of roll I0. This again adjusts the tension on the cord. The effect is to keep the tension constant despite changes in the percentage stretch of the cord.

It is desirable that the dancer sheave operate within a predetermined range. This is accomplished by adjustment of turnbuckle 15. When the stretching operation is started, dancer rod 3| and pin i8 may rise or fall. Turnbuckle 15 is then turned by hand until rocker arm i9 is horizontal. Nuts 16 and 11 are then tightened.

Since the variable-speed mechanism is operated by the dancer, it is necessary that the force required to turn the rod 23 be small. A 44 to 1 mechanical ratio is employed. The parts are designed so that the difference in speed between rolls l0 and 1 is variable from zero difference to 17%. A 17% variation in speed is obtained with a 1A turn of crank rod 23.

Having thus described our invention, we claim:

1. A textile strand stretching apparatus comprising a forward roll and a rearward roll about each of which the strand is wrapped, the axes of the rolls being parallel to each other means for rotating the rolls to advance the strand from f rolls to tension said portion, said last-mentioned means including an element that moves in response to variations in the stretch in said portion, actuating means responsive to the movement of said element to cause the speed-varying means to increase said lag when the stretch increases and to decrease said lag when the stretch decreases, the means for rotating the rolls including a variable pitch sheave mounted for rotation about the axis of one of said rolls and being adjacent to and operatively connected to turn said one of the rolls, means providing a second variable pitch sheave rotating about the axis of the other roll and operatively connected to turn the said other roll, a V-belt for said sheaves, the said speed-varying means including means'for increasing the effective diameter of one of said sheaves and simultaneously decreasing the eilective diameter of the other o'f said sheaves.

2. The apparatus described in claim 1 in which each roll has a strand gripping V-shaped peripheral slot in which the strand seats, the comparative width and depth of the slot and of the strand being such that the sides of the strand are in contact with the V-shaped sides of the slot.

3. The apparatus described in claim 2 and a power-driven wind-up roll to which the strand passes from the forward roll, means for varying the speed of the wind-up roll to adjust its speed with respect to that of the forward roll to apply tension to the strand.

4. The apparatus described in claim 1, and a strand wind-up roll, means driven by the rotation of the forward roll to turn the wind-up roll, said means including means for varying the speed of the wind-up roll to adjust its speed with respect to that of the forward roll to apply tension to the strand.

5. The apparatus defined in claim 1 in which the means for applying a constant force comprises a sheave supported by the said strand portion and mounted upon a weighted standard, the actuating means including a lever operated by the movement of the standard and including means operated by the lever to operate the speedvarying means as recited in claim 1.

6. A textile strand stretching apparatus comprising rotary means providing a strand roll and providing a variable pitch sheave operatively connected to rotate with said roll, a second rotary means providing a second strand roll and providing a second variable pitch sheave operative to turn the second strand roll a shaft for each roll, the shafts being parallel, said sheaves being mounted by said shafts, the strand being wound about one roll and thereafter about the other, the strand rolls being in axially fixed positions upon the shafts, a V-belt driven by the ilrst sheave and driving the second sheave, each of said sheaves having opposed conical faces upon which the belt is seated, means for moving a conical surface of one of said sheaves toward its opposed conical surface and for simultaneously retracting a conical surface of the other sheave away from the opposed conical surface, whereby the sheaves are caused to rotate at different peripheral speeds to stretch the strand.

'7. The apparatus described in claim 6 in which each roll is grooved and is provided with a V- shaped peripheral slot inA which the strand is seated, and which contacts a substantial portion of the sides of the strand, the slot being in the innermost part of the groove.

8. The apparatus described in claim 6 and means for applying a constant force to that portion of the strand extending from one roll to the other roll to tension that portion, said means comprising a rotary member suspended by said strand portion and a standard upon which the rotary member is mounted, support means for the standard permitting free upward and downward movement of the latter, a lever operatively connected to be pivoted by the movement of the standard, a rocker arm, links adjustable in length operatively connected to convey the movement of the lever to said rocker arm, said means for simultaneously moving the conical surfaces comprising a rod mounted for rotation about its longitudinal axis, said rod having eccentrically disposed longitudinally extending pins, thrust means operatively mounted to move the conical surfaces as described, said pins operating said thrust means upon rotation of the rod by the rocker arm.

RAY C. YOUNG. JOHN J. BROWN.

REFERENCES CITED 'I'he following references are of record in the le of this patent:

UNITED STATES PATENTS Swanson Apr. 23, 1946 

